In the woodworking art, dovetail corner joints are very old and very well known. A dovetail joint is a woodworking technique for joining two boards or walls, generally in end-to-end relationship, in which the adjacent end portions are provided with a plurality of alternating tenons and mortises. Tenons are protruding fingers and mortises are correspondingly shaped grooves which receive the tenons from the opposite workpiece. Dovetailing can also be applied to corner joints wherein the tenons and mortises of one board or wall are arranged perpendicular to and interfit with the tenons and mortises of another board. So arranged, the walls may be separated only by a force exerted in one direction, but will resist separation by a force perpendicular thereto. This is helpful in designing furniture in which more stress occurs in a given direction than in a perpendicular direction, such as at rear corners of drawers.
Most dovetail type corner joints have the tenons and mortises of each member cut entirely through the wall thickness thereof, so that the tenons and mortises of both walls are visible from the outside of the joint. A few dovetail type corner joints provide tenons cut in the same way, but the mortises and tenons on one of the walls are "blind". That is, the tenons and mortises extend only partially through the wall thickness of one of the boards, so that when the tenon is inserted into the mortise, the dovetailing effect is visible from the outside of one wall only. When looking at the other wall of the corner, the joint is not visible.
Further, on the partially hidden dovetail joints known previously an entirely separate cutting head is necessary to form the male and female members.